Sensing mechanism for slicing machine control system

ABSTRACT

A mechanism for sensing the cross-sectional area of a slab of a food product during processing, as in a slicing machine where the slab is cut into drafts of predetermined weight. As the slab is advanced into the slicing blade, sensing fingers ride on the top and one side surface of the slab and respond to changes in the thickness and the width of the slab. The mechanism through a multiplier coupling provides a mechanical output indicative of the product of the thickness and the width, and is employed to drive the rotor of a step switch which, in conjunction with digital circuitry, serves to convert the mechanical output into a slice number signal for use by the electrical control apparatus of the slicing machine.

United States Patent n 1 Mathews, Jr.

1 SENSING MECHANISM FOR SLICING MACHINE CONTROL SYSTEM [75] Inventor: Victor M. Mathews, Jr., Kansas City,

Kans.

[73] Assignee: MKC Electronics Corporation,

Kansas City, Kans.

[22] Filed: Aug. 31, 1971 [21] Appl. No.: 176,619

I 1 Oct. 2, 1973 3,131,739 5/1964 Harrington 146/95 Primary Examiner-Willie G. Abercrombie Att0rneyD. A. N. Chase [57] ABSTRACT A mechanism for sensing the cross-sectional area of a slab of a food product during processing, as in a slicing machine where the slab is cut into drafts of predetermined weight. As the slab is advanced into the slicing blade, sensing fingers ride on the top and one side surface of the slab and respond to changes in the thickness and the width of the slab. The mechanism through a multiplier coupling provides a mechanical output indicative of the product of the thickness and the width, and is employed to drive the rotor of a step switch which, in conjunction with digital circuitry, serves to convert the mechanical output into a slice number signal for use by the electrical control apparatus of the slicing machine.

11 Claims, 11 Drawing Figures PATENTED 21915 3.762.257

sum 3 BF 3 I26 60 5 5a 63 I7 I 80 I24 //VVENTOR. Vicror M. Mai hews Irv ATOTORNEY SENSING MECHANISM FOR SLICING MACHINE CONTROL SYSTEM This invention relates to improvements in machines for processing slabs of food products and, in particular, to an improved dimensional sensing mechanism for automatically controlled bacon slicing machines.

In the copending application of Victor M. Mathews, Jr. et al., entitled Variable Count Slicing of Food Products, Ser. No. 859,514, filed Sept. l9, 1969, now US. letters Pat. No. 3,642,046, a method and apparatus are disclosed for determining the number of slices of a slab of a food product constituting a draft thereof of a predetermined weight. The apparatus is embodied in an automatic control system illustrated in conjunction with a bacon slicing machine. As a slab of bacon is advanced into the slicing blade, sensing fingers engage the top of the slab to determine the slab thickness. This determination forms an information input to digital control circuitry that derives a slice count from the information representing the number of slices needed to constitute a draft of desired weight, such as one pound. A counter monitors the rotating slicing blade and registers the number of slices actually cut. Accordingly, when the actual slice count reaches the slice number derived from the sensing fingers, the slab feed is momentarily interrupted. The bacon slices are deposited on a moving conveyor, thus the interruption in the feed spaces successive drafts so that the beginning and ending of each draft is evident.

The thickness of a slab of bacon is the primary variable dimension, but the width may also vary somewhat thereby rendering any control system subject to inaccuracies if dependent solely upon the sensed slab thickness. To compensate for variations in the width of the slab, the system in the aforesaid application employs a side sensing finger in engagement with one edge or side surface of the advancing slab. The speed of the slab feed is varied in accordance with changes in width sensed by the side finger, thereby producing minor variations in the thickness of each slice of bacon to compensate for changes in width.

One very desirable feature of the count control system of the aforesaid application is that the number of slices in a draft is varied to compensate for changes in the thickness of the slab, rather than varying the thickness of individual slices as in some prior art systems. Additionally, digital control circuitry is insensitive to line voltage, and is not adversely affected by the severe environmental conditions oftentimes encountered in meat packing plants. Although minor variations in slice thickness are produced by the width sensor, such variations are not distinguishable by normal observation. However, additional valve components in the hydraulic drive of the slab feed are required in order to provide the width responsive speed variation.

It is, therefore, an important object of this invention to provide a dimensional sensing mechanism for an automatic slicing machine control of the type discussed above, wherein the slice count for an individual draft is dependent upon both the thickness and the width of the slab in order to provide complete count control of the slicing machine without the need to vary the speed of the slab feed to compensate for width variations.

Furthermore, it is an important object of this invention to provide a dimension sensing mechanism for a food processing machine in which a slab of a food product is advanced past a measuring station, wherein such mechanism is capable of delivering an output indicative of the product of primary and secondary, transverse variable dimensions of the advancing slab through the use of a multiplier coupling between sensing fingers of the mechanism and the output member thereof.

In the drawings:

FIG. 1 is a perspective view of a bacon slicing machine provided with the sensing mechanism of the present invention, the machine being viewed from the side and rear thereof;

FIG. 2 is an enlarged, fragmentary, side elevational view of a portion of the mechanism housing and the step switch. thereabove to which the output of the mechanism is connected (viewed from the left side in FIG. 1), parts being broken away to reveal details of construction;

FIG. 3 is a rear elevational view of the sensing mechanism, the housing thereof and the surrounding components of the machine being removed for clarity;

FIG. 4 is a vertical sectional view taken along line 44 of FIG. 3;

FIG. 5 is a side elevational view of the mechanism of FIG. 3, as seen from the left side of the machine in FIG. 1 with the housing of the mechanism removed, parts being broken away to reveal details of construction;

FIG. 6 is a top plan view of the mechanism of FIG.

FIG. 7 is a detail view showing the pivotal connection of the coupling device with the output member;

FIG. 8 is a diagrammatic view showing the positions of the components of the mechanism during sensing of a slab of given thickness and width;

FIG. 9 is a view similar to FIG. 8 but showing the changed positions of the mechanism components in response to an increase in slab thickness;

FIG. 10 is a view similar to FIG. 8 but showing the changed positions of the mechanism components in response to an increase in the width of the slab; and

FIG. 11 is an electrical schematic diagram showing a portion of the digital circuitry associated with the step switch.

TI-IE SLICING MACHINE Referring to FIG. 1, a bacon slicing machine is illustrated which, insofar as its basic mechanical components are concerned, is of standard design. The machine has a rectangular base 20 supported on legs 22. A stationary table 24 overlies the base 20 and extends longitudinally thereof from the rear of the machine (closest to the viewer) to the front of the machine where a rotary slicing blade 26 is mounted. The blade 26 is disposed within a cover 28 and is attached to the forward end of a shaft 30 that extends substantially the length of the machine above the table 24. A drive motor (not shown) for the shaft 30 is enclosed within a shroud 32 adjacent the rear of the machine.

A reciprocable carriage 34 overlies the table 24 and is utilized as a ram or pusher to advance a slab of bacon (not shown) on table 24 into the slicing blade 26 through an opening 36 in the front wall of the machine. The advancing slab passes a measuring station broadly denoted 38 where the thickness and the width of the slab are sensed by a dimensional sensing mechanism 40. A cabinet 42 above the mechanism 40 houses mechanical and electrical components of the automatic control, which is preferably a variable count slicing control of the general type disclosed in the aforesaid application Ser. No. 859,514. The drive for the carriage 34 is hidden from view by the shroud 32, but would commonly comprise a double-acting hydraulic piston and cylinder assembly.

THE SENSING MECHANISM The sensing mechanism 40 of the present invention is illustrated particularly in FIGS. 3-7 with incidental reference to FIG. 1. Four sensing fingers 44, 46, 48 and 50 are spaced across the table 24 at its forward end adjacent the opening 36. These four fingers 44-50 ride on the top surface of the slab for the purpose of sensing the thickness of the slab at four spaced points, just prior to introduction of the leading edge of the slab into the slicing blade 26. A side sensing finger 52 is fixed to an upright pivot shaft 54 and engages the adjacent edge or side of the slab at approximately the same transverse zone thereof as the top fingers 44-50. The side finger 52 is responsive to variations in the width of the slab, and the cumulative sensing of all of the fingers 44-52 is employed to actuate an output member 56 in a manner to be subsequently explained.

A horizontal mounting bar 58 is secured to the front wall of the machine a short distance above the opening 36 and carries a pair of side plates 60. The output member 56 is in the nature of a laterally extending arm pivotally mounted intermediate its ends at 62 where it passes through an opening in the right side plate 60 (as viewed in FIGS. 3 and 6). The inner end of the arm 56 is provided with a longitudinal slot 64 and is received within a guide formed by a horizontally extending channel element 66. The element 66 forms a part of a coupling device broadly denoted 68, which includes a vertically reciprocable, T-shaped component 70. The channel element 66 is an integral part of the T-shaped component 70 and forms the top of the T as is clear in FIGS. 3 and 7.

A center supporting piece 72 is rigid with the mounting bar 58 and extends downwardly therefrom midway between the side plates 60. The piece 72 carries a U- shaped nylon bushing 74 which receives the stem 76 of the T-component 70. The stem 76 is captured by a horizontal antifriction roller 78 spanning the wings of the bushing 74, thus the stem 76 (and hence the entire component 70) is permitted to reciprocate vertically along a path of travel that may be considered to be generally about the pivotal axis 62 of the arm 56.

A horizontal pivot pin 80 (parallel to axis 62) is held by a carrier 82 which is of inverted, U-shaped configuration as viewed in FIG. 4. The carrier 82 fits over the channel element 66 with the depending wings 84 thereof disposed on opposite sides of the element 66 as is best seen in FIG. 4. The pivot pin 80 spans the wings 84 and extends through a pair of aligned, horizontally extending slots 86 in the channel element 66. The pivot pin 80 also passes through the slot 64 in the inner end of the arm 56 received within the element 66, thus the vertically reciprocable T-component 70 and the swingable arm 56 are joined by the pivot pin 80.

A center link 88 is pivotally attached to the T- component 70 by a pivot pin 90. The link 88 pivots about its center, the opposed ends thereof pivotally supporting a pair of shorter, end links 92 and 94. Each of such end links also pivots about its center, the outboard and inboard ends of the link 92 being connected to a pair of upper arms 96 and 98 respectively. An upper, horizontal shaft 100 spans the side plates 60 and serves to pivotally mount the arms 96 and 98 adjacent their upper ends as is clear in FIG. 5. The lower ends of the arms 96 and 98 are pivotally connected to fingers 44 and 46 respectively, the latter also being pivotally joined to the lower ends of a pair of lower arms 102 and 104. A lower shaft 106 parallel to the upper shaft pivotally mounts the lower arms 102 and 104 at their upper ends, thus a parallel linkage arrangement is provided for the fingers 44 and 46.

Similarly, the end link 94 has its ends connected to a pair of upper arms 108 and 110, the latter being pivotally mounted on the upper shaft 100. The finger 48 is secured by pivotal connections to the lower ends of arm 108 and a lower arm 1 12, the latter being pivotally mounted on shaft 106. Another identical parallel linkage arrangement is provided for the finger 50 by the arm 110 and a lower arm 114. Accordingly, the three a links 88, 92 and 94 form whiffle-tree levers which serve to mechanically average the thickness of the slab sensed by the fingers 44-50 at the four spaced points of contact of the fingers with the top surface of the slab. Three hold-down members 116 are mounted between the fingers 44-50 and are supported by a cross shaft 118 spanning the side plates 60, each member 116 being spring-biased downwardly by a suitable spring (not shown) contained within a mounting collar 120 that secures the upper end of the member 116 to the shaft 118. (The cross shaft 118 and members 116 are removed from FIGS. 3 and 6 for clarity.)

The pivot shaft 54 to which the side finger 52 is secured extends upwardly through a mounting extension 122 and is provided with a crank arm 124. As viewed in FIG. 3, the left end of a connecting link 126 is joined to the crank arm 124 by a pin 128, the connecting link 126 being mounted for horizontal reciprocation in a guide slot 130 in an upright, cylindrical nylon bearing member 132 supported on a cross bar 134 spanning the side plates 60. The right end of the connecting link 126 is apertured to slidably receive a vertical coupling pin 136 depending from a lug 138 on the carrier 82. The pivot shaft 54 continues upwardly through a journal block 140, a return spring 142 being connected to the upper end of the shaft 54 to yieldably bias the same in a clockwise direction as viewed in FIG. 6. A vertical plate 144 serves as a stop for the crank arm 124 to limit rotation of the shaft 54 under the bias of the spring 142. The crank arm 124 in the Figures is shown engaging the stop 144, thus the side finger 52 is disposed at its maximum inward position. The side finger 52 swings outwardly upon contact by an advancing bacon slab, causing rightward shifting of the connecting link 126 (as viewed in FIG. 3) to shift the carrier 82 to the right. The approximate mid position of the side finger 52, corresponding to a slab of approximately average width, is illustrated in FIG. 7 where it may be seen that the pivot pin 80 has shifted to the right in the slots 86 as compared with FIG. 3.

THE ELECTRICAL CONTROL A step switch 146 is shown in FIG. 2 inside the cabinet 42, and comprises a swingable arm member 148 received within a vertical opening through a horizontal mounting bar 152 and pivotally secured thereto at 150. The member 148 carries a gear segment 154 in mesh with a pinion 156 keyed to a shaft 158 rotatably supported by the bar 152. A rotor 160 of non-magnetic material is fixed to the shaft 158 and is provided with a pair of diametrically opposed magnet holders 162, each of which carries a permanent magnet 164 as illustrated schematically in FIG. 11. A drum 166 of nonmagnetic, insulating material is mounted on bar 152 in coaxial alignment with the axis of the shaft 158, the inner surface of the drum 166 being in close proximity to the magnets 164 to thereby define a very narrow air gap between each magnet 164 and the adjacent portion of such inner surface.

A step switch of the type shown at 146 in FIG. 2 is fully shown and described in the aforesaid application Ser. No. 859,514, which is incorporated herein by reference as may be necessary for a full and complete understanding of the construction and operation of the step switch 146.

As in the aforesaid application, two banks of normally open reed switches 168 are embedded in the drum 166 and are simultaneously swept by the two magnets 164 carried by the magnet holders 162. A portion of the drum 166 is broken away in FIG. 2 to reveal several of the reed switches 168, and a portion of one of the banks of switches 168 is shown schematically in FIG. 11 in a planar layout for clarity of illustration. One of the permanent magnets 164 is illustrated in phantom lines and may be considered to be a rectilinearly movable switch element having a plurality of switch positions representing different slice numbers, such as 18, 19" and 20. At each switch position two series connected reed switches are closed to establish electrical continuity from a common lead 170 through the two closed switches. It may be appreciated in FIG. 11 that the particular switch position illustrated is that position corresponding to actuation (closure) of the upper reed switch 168 of each of the two groups of three, which represents a slice number of 18.

Referring to FIG. 2, it may be seen that an upright connecting rod 172 is pivotally joined at its lower end to the swingable arm or output member 56 of the sensing mechanism 40, the upper end of the rod 172 being pivotally joined at 174 to the swingable arm member 148 of the step switch 146. Accordingly, as the output member 56 is swung through a range of output positions in response to the sensing fingers 4452, the rotary switch element (magnets 164) assumes a corresponding switch position representing a particular slice number. This number is employed by digital circuitry to control the advancement of the carriage 34 of the machine, in accordance with the principles of operation set forth in the aforesaid application.

OPERATION The thickness and the width of the slab is sensed continuously by the fingers 4452 as the slab is advanced past the measuring station 38 into the slicing blade 26. The mechanical output of the four top fingers 4450 is represented by the vertical position of the T- component 70, since the center link 88 is pivotally connected thereto. As the T-component 70 moves upwardly and downwardly generally about the axis 62 of the output member 56, such member is caused to swing and the degree of upward displacement of the connecting rod 172 is indicative of the average thickness of the slab.

Now assuming that the width of the slab also varies, the finger 52 engaging the edge of the slab is thereby caused to swing outwardly and inwardly in accordance with increasing and decreasing slab widths. As the side finger 52 is forced outwardly by an increasing width dimension, the shaft 54 rotates against the action of the return spring 142 to shift the connecting link 126 to the right as viewed in FIG. 3. This, in turn, shifts the carrier 82 to the right to force the pivot pin 80 to advance horizontally to the right in the slots 86 in the channel guide element 66. This shortens the distance between the pivot pin 80 and the axis 62. If the thickness of the slab remains constant, this action causes the connecting rod 172 on the outer end of the output member 56 to shift upwardly since the pivot pin 80 is also forced to traverse the slot 64 in the inner end of the output member 56. In this respect, a comparison of FIGS. 3 and 7 illustrates the manner in which rightward movement of the pivot pin 80 forces the inner end of the member 56 downwardly as the distance between the pin 80 and the axis 62 is shortened.

The operation of the mechanism 40 just discussed may be readily appreciated from viewing FIGS. 8, 9 and 10. Assuming that FIG. 8 shows the beginning positions of the components of the mechanism, FIG. 9 then shows the positions of such components in response to an increase in the thickness of the slab. Note that the T-component has dropped as compared with FIG. 8 under the upward movement of the sensing fingers 44-50, causing the outer end of the output member 56 to elevate. The width remains unchanged.

In FIG. 10 the thickness of the slab is the same as in FIG. 8 but the width has now increased. Accordingly, the carrier 82 has shifted to the right to cause the outer end of the output member 56 to move upwardly as indicated by the arrow. Therefore, an increase in the crosssectional area of the advancing slab, whether due to an increase in thickness as shown in FIG. 9, or an increase in width as shown in FIG. 10, effects upward movement of the rod 172 connected to the step switch mechanism.

It may also be appreciated that the degree of swinging movement of the output member 56 in response to changes in width will be dependent upon both the extent that the pivot pin is shifted to the right and the vertical position of the T-component 70. The thicker the slab, the lower the position of the component 70 and thus the greater the angle formed by the slot 64 in the member 56 and the slots 86 in the guide element 66. As this angle increases, the same degree of rightward movement of the pivot pin 80 causes a correspondingly greater change in the position of the output member 56. Furthermore, since the distance between the pivot pin 80 and the axis 62 is shorter the greater the width of the slab, the degree of movement of the output member 56 increases with increasing width for the same vertical displacement of the T-component 70 in response to thickness variations. in this manner a multiplier coupling is formed between the top and side sensing fingers and the output member 56 so that the position of the step switch 146 will be controlled by both transverse dimensions of the advancing slab.

Referring to FIG. 11 a counting pulse 176 is illustrated appearing on the common lead 170. The pulse 176, in accordance with the teachings of the aforesaid application, is produced at a selected slice count at which it is desired to sample the size of the advancing slab. FIG. 11 illustrates one of the magnets 164 of the step switch 146 in a position effecting closure of the two upper reed switches 168 of the two groups thereof illustrated, such closure representing a determined slice number of 18. Accordingly, the pulse 176 is conducted to the output lead identified 18 to provide a slice number signal that is employed as an electrical input to the control apparatus (not shown) which produces an output command at the time that the 18th slice is cut, such command normally being employed to deactivate the slab feed in synchronism with the cutting of the 18th slice of the draft. Manifestly, as the crosssectional area of the slab changes, the positions of the magnets 164 are caused to change correspondingly to develop different slice numbers for succeeding drafts depending upon the dimensions sensed by the fingers 44-52.

I claim:

1. In a food processing machine where a slab of a food product is advanced past a measuring station, a sensing mechanism at said station for delivering an output indicative of the product of primary and secondary, transverse variable dimensions of the advancing slab, said mechanism comprising:

first shiftable sensing finger means engageable with a surface of said slab and responsive to changes in said primary dimension;

second shiftable sensing finger means engageable with a second surface of said slab and responsive to changes in said secondary dimension;

a movable member for providing said output;

means mounting said member for swinging movement through a range of output positions; and

a multiplier coupling device spaced from the axis of swinging movement of said member and connecting said first and second finger means with said member,

said device being responsive to shifting of said first and second finger means for swinging said member through a displacement representing the change in the product of said dimensions to cause the output position assumed by said member to be dependent upon the product of said dimensions as sensed by said first and second finger means.

2. The mechanism as claimed in claim 1,

said device moving along a path of travel generally about said axis in response to shifting of said first finger means,

said device having a pivotal connection with said member shiftable transversely of said path; and

means coupling said second finger means to said connection for shifting the latter transversely of said path to decrease or increase the distance between said connection and said axis in accordance with an increase or a decrease, respectively, in said secondary dimension.

3. The mechanism as claimed in claim 1,

said device moving along a path of travel generally about said axis in response to shifting of said first finger means for effecting said swinging of the member in accordance with changes in said primary dimension,

said device having a pivotal connection with said member shiftable transversely of said path to vary the distance between said connection and said axis;

and

means coupling said second finger means to said connection for shifting the latter transversely of said path in accordance with changes in said secondary dimension and independently of movement of said device along said path,

said connection upon said shifting thereof effecting said swinging of the member to a degree dependent upon the extent said connection is shifted and the position of said device along said path.

4. The mechanism as claimed in claim 1,

said device moving along a path of travel generally about said axis in response to shifting of said first finger means,

said device including a guide extending transversely of said path, and a pivot for said member shiftable in said guide,

said member receiving said pivot for movement of the pivot along the member toward and away from said axis; and

means coupling said second finger means to said pivot for shifting the latter along said guide to decrease or increase the distance between said pivot and said axis in accordance with an increase or a decrease, respectively, in said secondary dimension.

5. The mechanism as claimed in claim 4,

said guide comprising an elongated channel element,

said member including an arm having opposed ends with said axis disposed intermediate said ends, one end of said arm being received by said channel element and the latter and said one end having longitudinal slots therein receiving said pivot.

6. The mechanism as claimed in claim 4,

said device further including a shiftable carrier supporting said pivot and provided with a coupling pin extending in parallelism with said path,

said coupling means including a connecting link between said second finger means and said pin slidably receiving the pin to interconnect the link and the pin irrespective of the position of said device along said path.

7. In the machine as set forth in claim 1 where the slab is advanced into cutter means to cut the slab into slices and where control apparatus is employed which produces an output command when the number of said slices constitutes a draft of said food product of substantially a predetermined weight, said mechanism further comprising:

means coupled with said member for converting said output position of the member into an electrical input signal for said apparatus indicative of said number of slices required to constitute said draft.

8. In a machine for slicing a food product where a slab of said product is advanced into cutter means to cut the slab into slices, and where control apparatus is employed which produces an output command when the number of said slices constitutes a draft of said product of substantially a predetermined weight, mechanism for sensing primary and secondary, transverse variable dimensions of the advancing slab and for providing an electrical input to said apparatus indicative of said number of slices required to constitute said draft, said mechanism comprising:

first shiftable sensing finger means engageable with a surface of said slab and responsive to changes in said primary dimension;

second shiftable sensing finger means engageable with a second surface of said slab and responsive to changes in said secondary dimension;

a step switch provided with a shiftable switch element having a plurality of switch positions representing different slice numbers;

operating means coupled with said switch element and said first and second sensing finger means for shifting said element in accordance with said changes in the primary and secondary dimensions,

said operating means delivering a mechanical output to said element representing the product of said primary and secondary dimensions; and

circuitry coupled with said switch for producing a slice number signal comprising said electrical input in accordance with the position of said element.

9. The mechanism as claimed in claim 8,

said operating means including a movable member for providing said mechanical output, means mounting said member for swinging movement through a range of output positions, a coupling device spaced from the axis of swinging movement of said member and connecting said first and second finger means with said member, said device being responsive to shifting of said first and second finger means for swinging said member through a displacement representing the change in the product of said dimensions to cause the output position assumed by said member to be dependent upon the product of said dimensions as sensed by said first and second finger means, and means connecting said member with said element to shift the latter to the switch position thereof corresponding to the output position of the member.

10. In a machine for slicing a food product,

means for advancing a slab of said product at a constant speed into cutter means to cut the slab into slices;

control means responsive to slab size information for producing an output command when the number of said slices constitutes a draft of said product of substantially a predetermined weight; and

mechanism for sensing primary and secondary, transverse variable dimensions of the advancing slab and for delivering an output constituting said slab size information, said mechanism including:

1. first shiftable sensing finger means engageable with a surface of said slab and responsive to changes in said primary dimension,

2. second shiftable sensing finger means engageable with a second surface of said slab and responsive to changes in said secondary dimension,

3. an output member coupled with said control means and movable through a range of output positions to provide said slab size information, and

4. a multiplier coupling device connecting said first and second finger means with said member, and responsive to shifting of said first and second finger means for moving said member through a displacement representing the change in the product of said dimensions to cause the output position assumed by said member to be dependent upon the product of said dimensions as sensed by said first and second finger means.

11. In the machine as claimed in claim 10, said control means including circuitry responsive to the output position of said member for producing a slice number signal indicative of said number of slices required to constitute said draft.

* t l I! 

1. In a food processing machine where a slab of a food product is advanced past a measuring station, a sensing mechanism at said station for delivering an output indicative of the product of primary and secondary, transverse variable dimensions of the advancing slab, said mechanism comprising: first shiftable sensing finger means engageable with a surface of said slab and responsive to changes in said primary dimension; second shiftable sensing finger means engageable with a second surface of said slab and responsive to changes in said secondary dimension; a movable member for providing said output; means mounting said member for swinging movement through a range of output positions; and a multiplier coupling device spaced from the axis of swinging movement of said member and connecting said first and second finger means with said member, said device being responsive to shifting of said first and second finger means for swinging said member through a displacement representing the change in the product of said dimensions to cause the output position assumed by said member to be dependent upon the product of said dimensions as sensed by said first and second finger means.
 2. second shiftable sensing finger means engageable with a second surface of said slab and responsive to changes in said secondary dimension,
 2. The mechanism as claimed in claim 1, said devIce moving along a path of travel generally about said axis in response to shifting of said first finger means, said device having a pivotal connection with said member shiftable transversely of said path; and means coupling said second finger means to said connection for shifting the latter transversely of said path to decrease or increase the distance between said connection and said axis in accordance with an increase or a decrease, respectively, in said secondary dimension.
 3. The mechanism as claimed in claim 1, said device moving along a path of travel generally about said axis in response to shifting of said first finger means for effecting said swinging of the member in accordance with changes in said primary dimension, said device having a pivotal connection with said member shiftable transversely of said path to vary the distance between said connection and said axis; and means coupling said second finger means to said connection for shifting the latter transversely of said path in accordance with changes in said secondary dimension and independently of movement of said device along said path, said connection upon said shifting thereof effecting said swinging of the member to a degree dependent upon the extent said connection is shifted and the position of said device along said path.
 3. an output member coupled with said control means and movable through a range of output positions to provide said slab size information, and
 4. a multiplier coupling device connecting said first and second finger means with said member, and responsive to shifting of said first and second finger means for moving said member through a displacement representing the change in the product of said dimensions to cause the output position assumed by said member to be dependent upon the product of said dimensions as sensed by said first and second finger means.
 4. The mechanism as claimed in claim 1, said device moving along a path of travel generally about said axis in response to shifting of said first finger means, said device including a guide extending transversely of said path, and a pivot for said member shiftable in said guide, said member receiving said pivot for movement of the pivot along the member toward and away from said axis; and means coupling said second finger means to said pivot for shifting the latter along said guide to decrease or increase the distance between said pivot and said axis in accordance with an increase or a decrease, respectively, in said secondary dimension.
 5. The mechanism as claimed in claim 4, said guide comprising an elongated channel element, said member including an arm having opposed ends with said axis disposed intermediate said ends, one end of said arm being received by said channel element and the latter and said one end having longitudinal slots therein receiving said pivot.
 6. The mechanism as claimed in claim 4, said device further including a shiftable carrier supporting said pivot and provided with a coupling pin extending in parallelism with said path, said coupling means including a connecting link between said second finger means and said pin slidably receiving the pin to interconnect the link and the pin irrespective of the position of said device along said path.
 7. In the machine as set forth in claim 1 where the slab is advanced into cutter means to cut the slab into slices and where control apparatus is employed which produces an output command when the number of said slices constitutes a draft of said food product of substantially a predetermined weight, said mechanism further comprising: means coupled with said member for converting said output position of the member into an electrical input signal for said apparatus indicative of said number of slices required to constitute said draft.
 8. In a machine for slicing a food product where a slab of said product is advanced into cutter means to cut the slab into slices, and where control apparatus is employed which produces an output command when the number of said slices constitutes a draft of said product of substantially a predetermined weight, mechanism for sensing primary and secondary, transverse variable dimensions of the advancing slab and for providing an electrical input to said apparatus indicative of said number of slices required to constitute said draft, said mechanism comprising: first shiftable sensing finger means engageable with a surface of said slab and responsive to changes in said primary dimension; SECOND shiftable sensing finger means engageable with a second surface of said slab and responsive to changes in said secondary dimension; a step switch provided with a shiftable switch element having a plurality of switch positions representing different slice numbers; operating means coupled with said switch element and said first and second sensing finger means for shifting said element in accordance with said changes in the primary and secondary dimensions, said operating means delivering a mechanical output to said element representing the product of said primary and secondary dimensions; and circuitry coupled with said switch for producing a slice number signal comprising said electrical input in accordance with the position of said element.
 9. The mechanism as claimed in claim 8, said operating means including a movable member for providing said mechanical output, means mounting said member for swinging movement through a range of output positions, a coupling device spaced from the axis of swinging movement of said member and connecting said first and second finger means with said member, said device being responsive to shifting of said first and second finger means for swinging said member through a displacement representing the change in the product of said dimensions to cause the output position assumed by said member to be dependent upon the product of said dimensions as sensed by said first and second finger means, and means connecting said member with said element to shift the latter to the switch position thereof corresponding to the output position of the member.
 10. In a machine for slicing a food product, means for advancing a slab of said product at a constant speed into cutter means to cut the slab into slices; control means responsive to slab size information for producing an output command when the number of said slices constitutes a draft of said product of substantially a predetermined weight; and mechanism for sensing primary and secondary, transverse variable dimensions of the advancing slab and for delivering an output constituting said slab size information, said mechanism including:
 11. In the machine as claimed in claim 10, said control means including circuitry responsive to the output position of said member for producing a slice number signal indicative of said number of slices required to constitute said draft. 